Can you be more specific with this please? When you say you can't change, does that mean you've only got one resolution and you can switch from between fullscreen to windowed and that's it? If so, can you do this command and let me know what it returns?

All resolutions are available.When in Full Screen I can only use 1920x1080, if I select a different resolution and apply nothing happens, it still runs at 1920x1080. In windowed mode everything works well, changing the resolution works.Yes, one monitor only , printenv reports nothing.

LE: If I use 1280x720 resolution on the desktop, the game runs at that resolution in Full Screen, but it's the only one available.

Can't change resolution in full screen, either with the interface (which doesn't apply the change when you click 'Apply', and I can't force the resolution using command line options either. If the engine runs fullscreen, it runs 1680x1050 (native res) regardless of what I do. As such the game is almost unplayable (this system's a few years old, so I have played 1280x800 or lower in the past on Windows, without problem).

The game crashes once it loads into a server if I run it in windowed mode. The sound starts chopping and then the engine just dies, dropping me back at the Steam client.